T hekry la bait



(No Model.)

J. H. LA BAU.

TELEGRAPH CALL BOX. No. 334,785. Patented Jan. 26, 1886.

\\\\\\\\\\ul Z aw. I A. x6: W W a; h/iilarjg s.

NITED STATES PATENT OFFICE.

JOHN HENRY LA BAU, OF NEW YORK, N. Y., ASSIGNOR TO THE NE\V HAVEN CLOCKCOMPANY, OF SAME PLACE.

TELEGRAPH CALL-BOX.

sPECIPICATIOIQ' forming part of Letters Patent No. 334,785, datedJanuary 26, 1856.

Application filed February 6, 1885. Serial No. 155,118. (No model.)

To aZZ whom it may concern:

Be it known that I, JOHN HENRY LA BAU, a resident of New York city, inthe county and State of New York, have invented an Improved TelegraphGall-Box, of which the following is a full, clear, and exactdescription, reference being made to the accompanying drawings, in whichFigure 1 is a central section of my improved telegraph call-box. Fig. 2is a face view of the same. Fig.3 is a detail sectional view of theappliances for shaping the same. Fig. 4. is an enlarged sectional Viewof part of said box.

This invention relates to a new construction of call-box for telegraphicpurposes-such as messenger-calls, &e.such boxes being made of plasticcomposition. The composition itself is not part of the presentinvention, as it has already been utilized for sundry purposes in thearts; but it is one that is rendered plastic by heat, analogous,therefore, to sealing-wax or other well-known non-conducting substance.

My invention consists, principally, in a box which has the inscriptiveletters and characters formed of the non-conducting substance of thebox, but in different color from the rest or body of the box, so thatsuch letters shall project from the face of the box, and be throughouttheir entire thicknesses of this different color.

In the drawings, the letter A represents the back of my improvedcall-box. B is the cylindrical shell of the same, and O is its face orfront. These three parts A B O constitute the body of the box, and areof suit-able size and shape. They are, by preference, joined byscrew-threads; but the call-box, instead of being made in three parts,may be made in two parts, if desired.

On the outer side of the face-plate 0 appear the letters and words thatare shown at a in Fig. 2. These letters or words it is the intention ofmy invention toform on the face of the box out of the non-conductingsubstance thereof, but throughout of different color, so that thelettering of the box by hand may be avoided, and so, also, that if aportion of a letter should chip off, that part of the letter beneathwill still have the different tint. In order to produce this effect, Iprepare a plate, D, (see Fig. 3,) in the face of which are engraved tothe proper depth the letters a, that are produced on the face 0. Intothe cavities thus produced in the plate D, I insert the composition,preferably in a finely powdered state, so that the cavities fortheseletters shall just be filled with this composition. Thenonconducting composition that is inserted into these cavities has thecolor of which it is desired to produce the letters on the box. Heat isnow applied to the plate D, so as to melt the particles of thecomposition, thereby filling the cavities with the solid letters. Theseare then allowed to cool and become hard. After this the plate D is madeuse of as the bottom of a mold, E, into which mold is in serted thecomposition for the plate 0, which composition is ofthe same characterand kind as that used in filling the letters, but of a totally differentcolor. In practice I prefer to make the body of the plate Gblack and theletters a a red. Vhen the composition O is in the mold D E, heat isagain applied, thereby remelting the contents of the cavities of theplate D, and also melting the substance of the contents of the mold, theeffect being that when afterward the mold is chilled the letters a a,throughout of red color, will adhere to the face of the black plate 0.

By first letting the letters harden and then filling in the plasticcomposition for the body of the plate 0, I prevent the two mixturesblending and forming uncertain outlines for the letters.

It will be seen that should any part of a letter a break off the rest ofthe letter behind the broken portion will still show the red color,thereby allowing the proper form of such letter to be still displayed.It will also be seen that the letters (6 a project from the face of theplate 0 of the box, and that they are therefore readily read and seen,even from the side.

The particular advantage of this invention is, that a box thus producedneed not have the lettering painted nor stenciled on, thus savingconsiderable hand-labor, and also that the letters are far lessdestructible than those which can be painted or stenciled onto suchplate being constructed with the projecting a box, and that the entirebox, together with letters a, the whole being composed of the itslettering, will be of non-conducting subsame kind of plasticcomposition, but the stance. composition of the letters being ofdifferent 15 The process herein described will be made I colorthroughout from the composition of the the subject of anotherapplication for a patent. face of the box, substantially as herein shownI claimand described. As a new article of manufacture,.the tele- JOHNHENRY LA BAU. graph call-box composed of the non-conduct- Witnesses: :0ing back A, non-conducting cylinder 13, and i CHARLES G. M. THOMAS,

non-conducting face-plate C, the said face- HARRY M. TURK,

